static File nonVoiceMegaMix() {
  File file = javaxDataDir("Generated Audio/non-voice-mega-mix.wav");
  new AudioInputStreamsCollector c;
  // TODO: files without markers
  for (File f : allRecordingsWithMarkers()) {
    Clip clip = spectro_clipFromFile(f);
    L<IntRange> ranges = markerIntRangesForWAV(f);
    ranges = invertIntRanges(ranges, 0, clip.getFrameCount());
    for (IntRange r : ranges)
      addClipPartToAudioCollector(clip, r, c);
  }
  c.writeToWAV(file);
  ret file;
}